Heretofore, the components of high voltage power supply devices of this kind were usually enclosed in a metal casing or mounted in an open metal frame to be eventually mounted in a compartment in a metal electrostatic cell. In either case, adequately insulating the high voltage components from the metal casing or frame required air gap clearances or more costly barriers or insulating material which substantially increased the size or cost of the device. Also, the mounting and arrangement of the components in these prior devices was such as to require the services of highly trained people to accomplish replacement of any inoperative component. In other prior devices of this kind, the components were frequently potted in a metal casing in a thermoplastic or thermosetting material which permitted reducing the size of the device somewhat but added the cost of potting and obviously precluded the replacement of any inoperative components.
Recently, electrostatic air cleaners which include a high voltage power supply device within their frames are frequently mounted in openings in the ceiling or sidewall of a living space between the joists or studs so that minimizing that portion of the opening occuppied by the high voltage power supply is highly desirable. It is also highly desirable in the interest of economy to construct and arrange the high voltage power supply device so that any of its components which become inoperative in use may be conveniently removed and replaced in the proper position in the field.